1. Field of the Invention
The present invention relates to a glass-ceramic substrate including a glass component and a ceramic component, that is, a low-temperature co-fired ceramic material and a multilayer wiring board using the same.
2. Description of the Related Art
In an insulating wiring board for a semiconductor chip, a technology relating to a glass-ceramic substrate (low-temperature co-fired ceramics (LTCC substrate)) that can be fired at low temperature not higher than 1000° C. so as to be fired together with conductor material and resistance material at the same time is disclosed (refer to, for example, Japanese Patent Laid-Open Application No. 1-132194 and Japanese Patent Laid-Open Application No. 5-211006). This substrate is produced in the following manner to construct a multilayer wiring board: first, a green sheet is formed; conductive lines are printed on the surface of the green sheet with conductor material and resistance material; a plurality of printed green sheets are laminated and pressed to form a laminated material; and then the laminated material is fired. This substrate is used as an LTCC module such as high-frequency superimposing module, antenna switch module, and filter module.
For the purpose of manufacturing a multilayer wiring board, for example, a porcelain composition of high thermal expansion that includes glass including SrO and filler including metal oxide having a coefficient of linear thermal expansion of 6×10−6/° C. or more within a temperature range of 40 to 400° C. and cordierite is disclosed as a porcelain composition to be used for a glass-ceramic substrate (see, for example patent Japanese Patent Laid-Open Application No. 2004-83373). Here, Japanese Patent Laid-Open Application No. 2004-83373 describes that, for example, quartz, forsterite, or enstatite is preferably used as the metal oxide. In this manner, the main object of Japanese Patent Laid-Open Application No. 2004-83373 is to provide such a low-temperature fired porcelain of high thermal expansion and low dielectric constant that is a porcelain of high thermal expansion having a coefficient of linear thermal expansion of 8×10−6/° C. to 15×10−6/° C. and having a low dielectric constant, that is, a dielectric constant of less than 7 at 1 MHz.